JIMMY Spratt should "reflect on his position" as chairman of Stormont's regional development committee after he admitted telling untruths, one of its members has said.
It comes after the DUP MLA was forced to apologise to opponents of the Maze peace centre whom he called "nutters" after previously flatly denying making the remarks.
The South Belfast MLA apologised when the assembly's official record showed he made the comment during an Office of the First Minister and Deputy First Minister committee meeting last week.
UUP leader Mike Nesbitt, who was chairing the committee, accused Mr Spratt of making the remark but was then subject to an astonishing tirade demanding he apologise for the accusation.
Mr Spratt has since apologised to the "genuine people who have expressed concerns about the Maze project".
It has also emerged that Mr Spratt threatened to take legal action against a News Letter journalist who challenged him with the Hansard version of events.
The DUP has already said it would not be disciplining Mr Spratt over the incident.
However, John Dallat of the SDLP believes Mr Spratt may have lost the confidence of members of the regional development committee, calling his chairmanship into question.
Mr Dallat said he needs to "seriously reflect on his position" as the committee's chairman.
"Really, it is up to political parties to ensure that whoever they put in positions as chair of committees have the respect and confidence of the members of that committee," he said.
He said confidence in Mr Spratt was "severely dented by this whole incident".
Mr Dallat said there was a range of difficult issues to be dealt with by the committee, adding: "I am aware that chairpersons are under stress and for all manner of reasons."
Sinn Fein, meanwhile, said that they had no issue with Mr Spratt continuing as chairman.
A spokesman for the party said: "Who is chairman of committees is up to individual parties so it is up to the DUP to decide whether or not that is appropriate."
The saga may also affect plans for a joint unionist candidate at future elections in south Belfast.
Mr Spratt's name has been mooted in the past as a possible single candidate from a unionist party capable of unseating the SDLP's Alasdair McDonnell.
However, asked if they could endorse Mr Spratt as a future unionist unity candidate, a spokesman for the UUP said the party was at present "focused solely on the 2014 European and local government elections".
Mr Spratt could not be reached for comment last night.
■ COMMENT: Jimmy Spratt, left, and John Dallat